The present invention relates to a refractory spout brick of the type which is molded from a refractory material, preferably a ceramic refractory material, and which has extending therethrough a throughflow opening in the form of a funnel-shaped inlet converging inwardly and downwardly to a throughflow duct.
Spout bricks of this general type are well known in the metallurgy art and are employed for a diverse number of operations wherein it is necessary to pour molten material, such as molten metal, from a container.
The present invention is further directed to such a refractory spout brick of the type further including a gas collecting space surrounding the throughflow duct, with a gas feed duct extending from the exterior to the gas collecting space, and with a lateral gas feed extending from the gas collecting space to the throughflow duct. Spout bricks of this general type are used, for example in continuous casting operations, particularly for the continuous casting of aluminum-killed steel.
The lateral feed of gas to the throughflow duct is variously employed for preventing the formation of deposits in the throughflow duct, and/or preventing the freezing of the melt when a slide closure is closed, and/or regulating the throughflow velocity of the metal melt, and/or metallurgically treating the metal melt.
Considerable effort has been made in the prior art to achieving efficient systems for laterally feeding gas to the throughflow duct of a spout brick.
In German DT-OS No. 20 12 691, there is shown a system wherein gas is flowed into a throughflow duct through the material of the spout brick itself, which is thus made permeable to gas, for the purposes of avoiding obstruction and narrowing down of the throughflow duct, as well as to avoid soiling of the throughflow duct. However, the arrangement of this German publication is disadvantageous in practice.
In U.S. Pat. No. 3,253,307, there is shown a system wherein gas is conducted to the throughflow duct from an annular duct which surrounds the throughflow duct through a plurality of radial inlet ducts, for the purpose of controlling the throughflow velocity of the metal melt. This arrangement is disadvantageous in operation. This U.S. patent also discloses permeating a gas laterally inwardly through an annular ceramic element. This arrangement does not however provide the necessary distribution, direction and velocity of the gas, since the gas merely bubbles through the relatively porous ceramic element. Additionally, sealing problems occur.
German Gebrauchmuster No. 69 18 019 discloses an arrangement wherein oxygen is blown through a radial duct into a throughflow duct to obtain a metallurgical treatment of steel, specifically a concentration of oxygen in the molten metal. This German disclosure also employs an oxygen duct which opens tangentially into the throughflow duct and which may be directed obliquely downwardly. This arrangement does not however result in entirely satisfactory results.
From the above discussion, it is believed that it will be apparent that the manufacture of known spout bricks is complex, particularly with regard to the provision of a system for supplying gas through the brick to the throughflow duct.